title: Polychlorinated biphenyl serum concentrations, lifestyle and time-to-pregnancy.
abstract: BACKGROUND
  Consumption of fish contaminated with polychlorinated biphenyls (PCBs) and prenatal PCB serum concentrations have been associated with a longer time-to-pregnancy (TTP). However, the relationship between preconception serum PCBs concentrations and TTP has not been previously studied.
  
  
  METHODS
  Eighty-three women (contributing 442 menstrual cycles) planning pregnancies completed daily diaries regarding menstruation, intercourse, home pregnancy test results, and reported use of alcohol and cigarettes. TTP denoted the number of observed menstrual cycles required for pregnancy. Preconception blood specimens underwent toxicologic analysis for 76 PCB congeners via gas chromatography with electron capture; serum lipids were quantified with enzymatic methods. A priori, PCB congeners were summed into a total and three groupings-estrogenic, anti-estrogenic and other-and entered into discrete analogs of Cox models with time-varying covariates to estimate fecundability odds ratios (FOR) and corresponding 95% confidence intervals (CIs).
  
  
  RESULTS
  Estrogenic and anti-estrogenic PCB concentrations (ng/g serum) conferred reduced FORs in fully adjusted models (0.32; 95% CI 0.03, 3.90 and 0.01: 95% CI < 0.00, 1.99, respectively). Reduced FORs (0.96) were observed for alcohol consumption standardized to a 28-day menstrual cycle in the same adjusted model (FOR = 0.96; 95% CI 0.93, 1.00).
  
  
  CONCLUSIONS
  These data suggest that environmental exposures including those amenable to change, such as alcohol consumption, may impact female fecundity. The findings are sensitive to model specification and PCB groupings, underscoring the need to further assess the impact of chemical mixtures on sensitive reproductive outcomes, such as TTP, especially in the context of lifestyle factors which are amenable to change, thereby improving reproductive health.
authors.affiliation: Epidemiology Branch, Division of Epidemiology, Statistics and Prevention Research, Eunice Kennedy Shriver National Institute of Child Health & Human Development, 6100 Executive Blvd, Rm. 7B03, Rockville, MD 20852, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Buck Louis
authors.forename: J
authors.initials: J
authors.lastname: Dmochowski
authors.forename: C
authors.initials: C
authors.lastname: Lynch
authors.forename: P
authors.initials: P
authors.lastname: Kostyniak
authors.forename: B M
authors.initials: BM
authors.lastname: McGuinness
authors.forename: J E
authors.initials: JE
authors.lastname: Vena
mesh_terms: D000328:Adult; D004781:Environmental Exposure / Q000032:analysis*; D005260:Female; D005306:Fertilization; D006801:Humans; D008019:Life Style; D008597:Menstrual Cycle / Q000097:blood; D011078:Polychlorinated Biphenyls / Q000097:blood*; D047489:Preconception Injuries; D011247:Pregnancy; D013997:Time Factors
chemical_list: D011078:Polychlorinated Biphenyls